Improvement in thread-tensions for sewing-machines



N. A. CONKLIN. Thread-Tefisi'on fer Sewing-Machine.

No. 206,774. Patented Aug. 6. 187-8.

i J G 4 Yi-PE 'ERS. PHOTD-LiKHOGRAFMER, WASHINGTON. D C

UNITED STATES PATENT OFFICE.

NATHANIEL CONKLIN, OF BROOKLYN, NElV YORK.

lMPROV EME-NT m THREAD-TEN'SIONS FOR SEWING-MACHINES.

Specification forming part of Letters Patent N0. 206,774, dated August6, 1878; application filed May 20, 1878.

To all whom it may concern:

Be it known that I, NATHANIEL A. OONK- LIN, of Brooklyn, in Kings countyand State of New York, have invented an Improved AutomaticThread-Tension for Sewing-Machines, of which the following is aspecification:

The object of my invention is to provide for furnishin g asewing-machine at the time of making each stitch, and in a simple andinexpensive manner, with the exact quantity of thread required to form astitch.

To this end the invention consists in the combination, with the meansfor operating the needle, of a tension device, whereby the threadrequired to form a stitch is caused to be drawn out on the descent ofthe needle-bar, and one portion of the thread is caused, directly orindirectly, to bind and hold another part, so as to obstruct the drawingof thread from the spool save at the proper time.

In the accompanying drawing, Figure 1 is a side view of a portion of asewing-machine embodying my invention. Fig. 2 is a detail viewillustrative of a modification of the invention. Fig. 3 is a side Viewof a portion of a sewing-machine embodying the invention in a modifiedform; and Fig. 4 is a plan or top view of a portion of thesewing-machine illustrated in Fig. 3.

Similar letters of reference designate corresponding parts in all thefigures.

Referring first to Fig. 1, A designates the frame of the sewing-machine.B designates a needle-bar arranged to reciprocate vertically in guidesat a, and O designates a vibratory needle-arm, supported by a pivot orstud, S, and operated, through a rod similar to that marked D in Fig. 3,by any suitable mechanism, so as to impart the requisite motion to theneedle-bar.

E designates a spool of thread supported on a suitable rod or holderextending from the frame A, so as to be free to turn in order that thethread may be unwound in the ordinary manner.

Gr designates a device consisting, in this example of my invention, ofan arm provided with eyes I) c, and extending from the frame A, it beingrepresented as secured thereto by mscrew-threaded shank entering thesame.

Inavc omitted in my drawings and shall omit in my description many ofthe elements ne'eessary to the operation of the sewing-machine, becausethey may be of any ordinary or wellknown construction, so far as myinvention is concerned.

The thread on its way from the spool E to the needle successively passesthrough the eye I) of the device G; thence through an eye, d, arrangedon the vibratory needle-arm or its equivalent; thence through the eye 0of the device G; thence around, through, or over a loose Wheel, 6, orits equivalent, arranged on the frame A; thence through the eye I) ofthe device G again, where it crosses a portion of itself; thence throughan eye, f, on the upper guide, a, of the needle-bar; and finally throughan eye, g, on the needle-bar and through the needle.

In Fig. 2 the thread, instead of passing twice through an eye, I), inthe device G, is made to pass first through a notch or fork, b, in saiddevice, and subsequently through a block, b fitting in said notch orfork, so as to be free to move up and down and bear upon the portion ofthe thread lying in the said notch or fork.

In both cases one portion of the thread is caused to bind and hold aportion nearer the spool E, so as to control the unwinding of the threadthereon, as I shall now more fully describe.

On the descent of the needle-arm 0 its eye d draws from the spool,through the eye I) or notch b of the device Gr, sufficient thread toreplace that used in forming theprevious stitch during the last upwardmotion of the needle; and on the ascent of the needle-arm and bar theportion of the thread which passes the second time through the eye b, orwhich passes through the block b, is caused to bind, directly orindirectly, through the block I), on the portion of the thread whichpasses first through the eye I), or which passes through the notch orfork b, with sufiicient force to obstruct the drawing of any thread fromthe spool until the completion of the stitch and the downward motion ofthe needle arm and bar releases the thread.

The modification shown in Fig. 2 is advantageous because the wearincident to direct contact of the crossing portions of the thread isavoided.

I do not claim in connection with this device the weight of a block, orits equivalent, on a thread for the purpose of producing a tension, nora block serving to clamp the thread so as to produce a tension thereon;but I consider that my particular method of actuating a block by oneportion of the thread so that it will operate at proper times uponanother portion is new and valuable.

\Vhenever practicable, open loops, recesses, or notches may be used inlieu of the eyes and without any blocks like the block b previouslydescribed.

ltet'erringnow to Figsi) and 4, the example of the device G here shownis provided with a 1 eye, It, and a pair of periplierieally-grooved wiecls, ll ll, secured on a single axle to rotate in unison, and formingpractically a single wheel, having two peripherieal grooves. The threadfrom the spool 1) passes through the eye It, is wound preferably twicearound the wheel ll, passes through the eye (I, is wound preferablytwice around the wheel H, (see Fig. 4,) and passes thence to the eyes fy and to the needle. The downward movement of the eye (1 during thevibration ot the needle-arm causes portions 1 and I. of the thread torotate the wheels Ii ll until the tension of portion 3 binds the threadon the wheel II and stops the rotation; but as there is only a nominaltension on parts 4 and 5 they readily slip to part 1 around the nowstationary wheel ll. When, during the ascent of the needle-arm, the eye11 approaches the wheels 11 II, the tension on portions 1 and 2 isrelaxed, the take-up at the needle draws the requisite thread from part3, and reverses the motion upon the wheel II, which, communicated to H,causes the latter to act as a brake on the thread and obstruct anyfurtncr withdrawal rom toe spool until the next descent of theneedle-arm, the stitch bcin g completed with a fixed amount of thread.

An important advantage of my invention is that, notwithstanding theobstruction ott'ered to the withdrawal of more thread than is requisitefor the formation of an ordinary stitch, a stout thread may slip at; itsextreme tension instead of breaking, and hence a long stitch throughthick material may be made.

It will be seen that by my invention 1 provide a simple, noiseless, andinexpensive tension, whereby, without the readjustment of any parts, theproper amount of thread for each stitch will be afforded and the sewingof tlifi'el ent thicknesses of material is facilitated.

hat I claim as my invention, and desire to secure by Letters Patent, is

1. In a scwingmachine, the combination, with the means for operating theneedle, ot'a tension device, whereby at certain times during theoperation of the needle one portion of the thread used in sewing iscaused, directly or indirectly, to bind or act as a brake on anotherportion, substantially as and for the purpose specified.

2. In a sewing-machine, the combination, with a vibratingneedle-arm,provided withan eye for the reception of the thread used insewing. of a fixed arm extending from the frame of the machine andprovided with two eyes for the reception of the said thread, wherebyduring the operation of the machine one portion of the thread is causedto directly bind or act as a brake on another portion, substantiall y asand for the purpose specified.

NATHANIEL A. CONKLIN.

Witnesses:

(HANDLER HALL, ()WEN PRENTISS.

